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Plant Conservation and the Mlynany Arboretum

Volume 2 Number 10 - June 1998

J. Takats, A. Kamenicka & M. Lanaková

Introduction

Since its foundation in 1892, the Arboretum Mlynany has evolved from a private botanic garden into a national protected area and an internationally known conservatory that is visited annually by over 100,000 people. Maintaining the ideals of the founder, Dr Stefan Ambrozy-Migazzi and his gardener Josef Misk, of concentrating as many foreign woody species as possible at this locale, the Arboretum houses over 2,100 taxa, representing 93 families. The Arboretum's collection comprises: deciduous angiosperms 65%, evergreen angiosperms 19% and gymnosperms 16%. Now under the auspices of the Slovak Academy of Sciences, this collection represents one of the most successful introductions of these plants into Central Europe.

The Arboretum is located in the foothills of the Carpathian Mountains, on the division between the central and western regions of the Slovak Republic. Its altitude is between 160 m and 206 m, the mean annual temperature is 9.2ºC. In July the mean day temperature is 19.3ºC and in January it is -2.8ºC. Precipitation averages between 500 mm and 600 mm annually. Snow cover usually lasts 42 days (December and January). Extremely cold winters were noted in 1929 and 1987; extremely dry summers were recorded in 1947, 1952, 1983 and 1992. Together, these extremes damaged or destroyed over half of the Arboretum's taxa.

Collections

The Arboretum covers 67 ha and is divided into five sections: Ambrozy's Park (36 ha), East Asian (14 ha), North American (7.5 ha), Korean (5.5 ha) and the Slovak Republic sections (4 ha). The most-represented families in the Arboretum are Caprifoliaceae, Rosaceae, Pinaceae, Ericaceae, Berberidaceae and Oleaceae.

Ambrozy's Park, the oldest section of the Arboretum, was originally an oak-hornbeam forest, but now contains over 200 taxa. Inspired by the diverse vegetation of southern Italy, Ambrozy-Migazzi and Misk first introduced Ilex aquifolium (now one of the most abundant species in this section), Erica carnea, Indigofera gerardiana, Juniperus virginiana, Laurocerasus officinalis and Pachysandra terminalis under the protective canopy of the oaks and hornbeams. As more plantings were made, the original forest was cut down. A small part of this forest remains and is being preserved in the newest section, representing the Slovak Republic.

Ex situ plantings on the slopes in the Slovak Republic section will correspond with in situ vegetative zones. This section currently contains Colutea arborescens, Pinus uncinata, Pyrus nivalis, Quercus pedunculiflora, Rhamnus saxatilis and Salix starkeane, among others. Representatives of over 250 additional taxa will be planted.

The Arboretum also includes two ponds and a series of creeks in the East Asia section. These artificial waterways were built to counteract the area's low humidity. This section was established in 1960 by I. Tomasko and now contains woody plants from China, Japan and the Caucasus and Himalaya mountains, including Actinidia kolomikta, Cercis chinensis and Pterocarya stenoptera. Other features include a Chinese pagoda and a Japanese garden house.

The North American area was established in 1975 on the site of former vineyards and orchards. This section is relatively new, but contains over 100 taxa, including Abies concolor, Quercus rubra, Liriodendron tulipifera, Pinus jeffreyi, Pinus rigida and Torreya californica. A distinguishing feature of the area is the Narcissus meadow located next to a reconstructed vineyard cottage.

The Korean section is divided into two parts: gymnosperms and angiosperms. This 5.5 ha area was established in 1984. Over 150 taxa currently grow in this part, including Acer grosserii, Amygdalus spp., Morus alba var. pendula and Pinus wallichiana.

Conservation of Plant Species

From its beginning, a major goal of the Arboretum has been to conserve plant species. Five approaches are used to achieve this goal:

Agency cooperation

The Arboretum collaborates with over 650 organizations. One of these organizations, the Institute of Forest Ecology, has a branch located in the grounds of the Arboretum. It has developed micropropagation procedures for the endangered Castanea sativa and Ledum palustre and decorative Rhododendron and Magnolia species. Other cooperating agencies are predominantly botanical gardens, arboreta and other organizations with whom seed and plant material are exchanged. These collaborations began in 1955.

Expeditions

In 1960, a first expedition was made to Tien Mu in China. Of the 197 species obtained, 99 were introduced into the then Czechoslovakia for the first time. The East Asia section was set up using the seeds and plant cuttings acquired. A second expedition was mounted in 1990.

Between the two China expeditions, three others were made to Korea in 1982, 1983 and 1985. In these expeditions, 160 species, represented by 6,000 seeds, cuttings and seedlings were procured from the Diamond Mountain, Mychangasan and Pectusan areas.

All the expeditions were thoroughly documented in Slovak. Translations of these documents into other languages are not currently available.

Herbarium

The herbarium (MLY) at the Arboretum Mlynany was established in 1990. In this herbarium, 14,191 items are indexed, 9,555 of these being from introduced species other than those from Korea or China. Of the other 5,636 species, 2,739 are from Korea and 1,897 from China.

Information about the indexed plant material is arranged alphabetically by genus and has been computerized in recent years. The computerization has enabled us to include maps showing the location of the woody plants in the Arboretum and in Europe.

Seed Storage

On arrival at the Arboretum, all plant material (seeds, cuttings, etc.) are indexed in the computerized database. Some seeds are kept in storage for exchange, research, planting or other future use.

Ex situ plantings

Seeds that are not stored and any live material obtained are grown in the arboretum's nursery. When the plants are hardy enough, they are transferred to the park or exchanged for other plants. The location of the plant, along with other information such as evidence of blooming and seeding is then noted in the arboretum's database. However, because many of the plants in the Arboretum are selfÄpropagating, some unrecorded specimens may exist. The last thorough update was done in 1990.

Although many plants have been introduced into the Arboretum, few receive any special winter protection. Palms are grown indoors and placed outdoors when weather permits. During cold weather, hotbeds are covered with dry bamboo sheets and hay.

Cultivar Development

The Arboretum Mlynany has developed new varieties of selected plant species. Thuja occidentalis 'Malonyana' and Quercus cerris 'Ambrozyana' were officially named in 1905 and 1906 respectively. Another five varieties (Cotoneaster cupressus 'Kavalovsky', Cotoneaster salicifolius 'Mlynany', Laurocerasus officinalis 'Misak', Laurocerasus officinalis selection Mlynany and Thuja occidentalis 'Misak') are awaiting official approval.

Future projects for the Arboretum include increasing signage, planting additional species in the Korean, North American and Slovak Republic sections and expanding the herbarium's computerized map to note all the in situ locations of indexed plant material.